Fence lizards are small, agile reptiles commonly found across North America, from the eastern United States to the western states and parts of northern Mexico. These lizards measure between 4 and 7.5 inches from snout to tail tip, displaying a gray to brown coloration. Their bodies are covered in distinctive spiny, rough scales. Males are particularly recognizable by the bright blue patches adorning their bellies and throats, especially prominent during the breeding season, while females often exhibit subtle black horizontal patterns.
These diurnal creatures actively hunt insects and bask in sunny spots on rocks, trees, or fences, which gives them their common name. They consume various invertebrates like beetles, ants, flies, caterpillars, and spiders, helping control local insect populations.
Lifespan in the Wild
The lifespan of fence lizards in their natural habitats can vary significantly, typically ranging from a few years to nearly a decade depending on the species and environmental conditions. Western fence lizards (Sceloporus occidentalis) commonly live for about 5 to 7 years in the wild, with some individuals potentially reaching 10 years. Eastern fence lizards (Sceloporus undulatus) generally have a wild lifespan of 2 to 5 years.
In northern regions, Eastern fence lizards may live longer, potentially 4 to 8 years, due to their ability to hibernate during colder months, which reduces their exposure to threats. However, many juveniles in both species do not survive past their first year due to high mortality rates.
Factors Affecting Longevity
Predation is a significant threat, with various animals hunting these lizards. Birds of prey, snakes like blue racers and rat snakes, larger lizard species, domestic cats, and wild mammals such as coyotes and bobcats regularly prey on them. Fence lizards employ camouflage, swift movements, and the ability to shed their tails as defense mechanisms.
The quality and availability of suitable habitat impact their survival. Ample shelter, such as rock crevices, fallen logs, and brush piles, is important for protection from predators and regulating body temperature. Habitat degradation and fragmentation, sometimes linked to urbanization, can reduce these resources, potentially impacting their survival rates.
Climate conditions, including temperature extremes and droughts, influence their longevity. While fence lizards can undergo brumation, a state of dormancy during winter, prolonged hot and dry periods can lead to dehydration and physiological stress. Consistent availability of food, primarily insects and spiders, and water sources is important. Scarcity of these resources can lead to malnutrition and weakened immune systems, making them more vulnerable to disease and parasites like botflies.
Extending Lifespan in Captivity
When cared for by humans, fence lizards can live considerably longer than their wild counterparts. This extended lifespan is due to the controlled environment, consistent nutrition, and protection from natural threats. An appropriate enclosure is important, with a minimum of a 10-20 gallon tank for a single lizard, though a 20-40 gallon or larger enclosure is preferable for climbing and a thermal gradient.
The enclosure should include a suitable substrate like coconut fiber or a soil mix, allowing for burrowing and maintaining some humidity. Multiple hiding spots are important to reduce stress, mimicking their natural need for secure retreats. Their diet should consist primarily of gut-loaded feeder insects such as crickets, mealworms, and dubia roaches. These insects must be dusted with calcium and multivitamin supplements to prevent nutritional deficiencies.
Temperature and lighting are important; a basking spot should reach 90-100°F, with ambient temperatures ranging from 75-85°F during the day, dropping to 70-80°F at night. Full-spectrum UVB lighting is important for vitamin D3 synthesis and proper calcium absorption, and should be provided for 12 hours daily. Hydration can be maintained through a shallow water dish, and misting the enclosure daily encourages drinking as fence lizards often prefer lapping water droplets.